A bug while <> symbol interpretation

Since using flatten in diamond wand,  this test below is not passed.

```
(test <>-symbol-interpretation-test
  (is (equal (-<>> (list 1 2 3 4 5)
               (mapcar (lambda (x) (-<> x (+ <> <>)))))
             (-<>> (list 1 2 3 4 5)
               (mapcar (lambda (x) (-<> x (+ <> <>))) <>)))))
```

Only using code walker solves this.
